Design and Manufacture of a 3D Printed GRID Collimator for Radiation Therapy

Abstract This study presents the design, fabrication, and evaluation of a 3D printed GRID collimator for spatially fractionated radiation therapy (SFRT). In this research, the mechanical and radiological performance of the 3D printed GRID collimators fabricated using polylactic acid (PLA), acrylonitrile styrene acrylate (ASA), and acrylonitrile butadiene styrene (ABS) materials were investigated. Mechanical stability of the GRID collimators was evaluated to assess load-bearing capacity and deformation behavior. Noticeable differences in the maximum load and deformation were observed for ABS, PLA, and ASA GRIDs. ABS material exhibited enhanced mechanical strength and superior resistance to deformation compared to PLA and ASA. The findings of the mechanical analysis illustrate the ABS 9.0 cm thickness GRID with 100% infill density exhibited the highest load-bearing capability, observed to be 2268 N at failure. Further, the percent depth dose and the peak-to-valley-dose ratio (PVDR) metrics of the GRID collimator were investigated using radiation to validate dose modulation capabilities. The dosimetry tests revealed that a higher PVDR (6.8) was achieved by the 9.0 cm ABS tungsten-filled GRID collimator with 100% infill density at 6 MV. Thus, this device with higher PVDR is preferred for the enhanced tumor control during the SFRT treatment. Our results demonstrate that 3D printed GRID collimators provide customized design, mechanically stable devices, and preferred dosimetry modulation.